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TEbe  mnfx>et*tt£  ot 


STUDY  OF  THE  DISTRIBUTION  OF 
IODINE  BETWEEN  CELLS  AND  COL- 
LOID IN  THE  THYROID  GLAND 


A  DISSERTATION 

SUBMITTED  TO   THE  FACULTY 

OF  THE  OGDEN  GRADUATE  SCHOOL  OF  SCIENCE 

IN  CANDIDACY  FOR  THE  DEGREE  OF 

DOCTOR  OF  PHILOSOPHY 

DEPARTMENT  OF  PHYSIOLOGICAL  CHEMISTRY  AND  PHARMACOLOGY 


BY 

HARRY  BENJAMIN  VAN  DYKE 


Private  Edition,  Distributed  By 

THE  UNIVERSITY  OF  CHICAGO  LIBRARIES 

CHICAGO,  ILLINOIS 


Reprinted  from 

'he  JOURNAL  OF  BIOLOGICAL  CHEMISTRY,  Vol.  XLV,  No.  2, 1921 ;  Vol.  LIV,  No.  i,  1922 
The  AMERICAN  JOURNAL  OF  PHYSIOLOGY,  Vol.  LVI,  No.  i,  1921 


tlntversitg'of 'Gbicago 


A  STUDY  OF  THE  DISTRIBUTION  OF 
IODINE  BETWEEN  CELLS  AND  COL- 
LOID IN  THE  THYROID  GLAND 


A  DISSERTATION 

SUBMITTED   TO   THE   FACULTY 

OF  THE  OGDEN  GRADUATE  SCHOOL  OF  SCIENCE 

IN  CANDIDACY  FOR  THE  DEGREE  OF 

DOCTOR   OF  PHILOSOPHY 

DEPARTMENT  OF  PHYSIOLOGICAL  CHEMISTRY  AND  PHARMACOLOGY 


BY 

HARRY  BENJAMIN  VAN  DYKE 


Private  Edition,  Distributed  By 

THE  UNIVERSITY  OF  CHICAGO  LIBRARIES 

CHICAGO,  ILLINOIS 


Reprinted  from 

The  JOURNAL  OF  BIOLOGICAL  CHEMISTRY,  Vol.  XLV,  No.  2, 1921;  Vol.  LIV,  No.  i,  1922 
The  AMERICAN  JOURNAL  OF  PHYSIOLOGY,  Vol.  LVI,  No.  i,  1921 


BfOLOGY 

LIBRARY 

G 


CXCHANGE 


.  ;  & 

Reprinted  from  THE  JOURNAL  OF  BIOLOGICAL  CHEZJ^TRY,  Vol.  XLV,  No.  2,  1921 


A  STUDY  OF  THE  DISTRIBUTION  OF  IODINE  BETWEEN 
CELLS  AND  COLLOID  IN  THE  THYROID  GLAND. 

II.  RESULTS  OF  STUDY  OF  DOG  AND  HUMAN  THYROID  GLANDS. 

BY  HARRY   BENJAMIN   VAN   DYKE. 

(From  the  Laboratory  of  Physiological  Chemistry  and  Pharmacology, 
.  University  of  Chicago,  Chicago.} 

(Received  for  publication,  November  29,  1920.) 

In  the  first  paper  of  this  series  Tatum1  described  a  method 
whereby  thyroid  cells  may  be  separated  from  colloid  material 
and  examined  chemically.  Briefly  the  method  consists  in  cutting 
frozen  sections  of  the  thyroid  gland  and  floating  these  sections 
on  Ringer's2  solution.  The  colloid  material  immediately  drops 
out  of  the  acini  and  is  presumably  dissolved  in  the  Ringer's  solu- 
tion. The  cells  may  then  be  separated  by  centrifugalization, 
dried,  weighed,  and  analyzed.  Comparisons  between  the  iodine 
content  of  cells  so  separated  and  the  iodine  content  of  control 
pieces  of  unsectioned  whole  gland  may  indicate  the  distribution 
of  iodine  between  cells  and  colloid  under  different  functional 
conditions. 

In  this  paper  I  wish  to  report  the  results  of  a  study,  suggested 
by  Dr.  A.  L.  Tatum,  of  the  distribution  of  iodine  in  the  thyroid 
glands  of  normal  and  iodine-fed  dogs  as  well  as  in  human  glands 
obtained  from  individuals  subjected  to  operation  for  toxic  goiter. 
The  method  earlier  described  by  Kendall3  was  used  in  making  the 
final  iodine  determinations. 

Incidental  to  the  determination  of  the  iodine  distribution  in 
dog  and  human  thyroid  glands,  some  control  experiments  were 
performed  relative  to  the  alterability  of  the  intracellular  iodine 
concentration  during  the  process  of  cutting.  It  may  be  argued 
that  a  portion  of  the  iodine-containing  compound  diffuses  from 

1  Tatum,  A.  L.,  J.  BioL  Chem.,  1920,  xlii,  47. 

2  Campbell,  J.  A.,  Quart.  J.  Exp.  Physiol.,  1911,  iv,  1,  Formula  "A." 

3  Kendall,  E.  C.,  J.  BioL  Chem.,  1914,  xix,  251. 

325 

THE  JOURNAL  OF  BIOLOGICAL  CHEMISTRY,  VOL.   XLV    NO.  2 


520421 


326  Distribution  of  Ibdme -In.  Thyroid  Gland.     II 


cells  as  they  lie  suspended  in  Ringer's  solution  during  the  sepa- 
ration of  the  colloid  material.  If  it  is  assumed  that  such  an 
outward  diffusion  takes  place,  it  seems  reasonable  to  expect  that 
the  iodine  compound  should  diffuse  back  into  the  cells  if  we  should 
increase  the  concentration  of  that  iodine  compound  in  the  Ringer's 
solution  in  which  the  cells  are  suspended.  Several  experiments 
like  those  given  in  Table  I  were  undertaken  to  determine  whether 
or  not  the  iodine  content  of  the  cells  could  thus  be  increased. 

TABLE  I. 

Effect  of  Floating  Cells  on  Pure  Ringer's  Solution  and  on  Ringer's  Solution 
on  Which  Cells  of  an  Iodine-Rich  Gland  Had  Been  Floated. 


Animal 
No. 

Weight 
of 
whole 
gland 
used. 

Iodine 
in 
whole 
gland. 

Weight 
of 
cell 
mass 
used. 

Iodine 
in 
cell 
mass. 

Ratio  of 
percentage  of 
iodine  in  cells 
to  percentage  of 
iodine  in 
whole  gland. 

Remarks. 

mg. 

percent 

mg. 

percent 

14 

146.0 

0.187 

40.5 

0.017 

0.091 

Cells  floated  on  pure  Ring- 

er's solution. 

53.0 

0.017 

0.091 

Cells   floated   on   Ringer's 

solution  on  which  previ- 

ously cells  of  iodine-rich 

gland  had  been  floated. 

20 

287.2 

0.030 

161.5 

0.005 

0.167 

Cells  floated  on  pure  Ring- 

er's solution. 

151.0 

0.006 

0.20 

Cells   floated   on   Ringer's 

solution  on  which  previ- 

ously cells  of  iodine-rich 

gland  had  been  floated. 

It  may  be  seen  from  the  data  given  in  Table  I  that  no  increase 
in  the  iodine  content  of  cells  could  be  brought  about  by  increas- 
ing the  concentration  of  the  characteristic  iodine  compound  in 
the  Ringer's  solution. 

Again  the  iodine  concentration  of  the  cell  mass  does  not  seem 
to  be  in  the  least  altered  whether  or  not  the  freshly  centrifugalizecl 
cell  mass  is  washed  several  times  with  iodine-free  Ringer's  solution. 

Moreover,  in  the  attempt  to  find  a  suspending  medium  more 
nearly  related  physicochemically  with  thyroid  cells  than  is  Rin- 
ger's solution,  I  have  used  fresh  dog  serum  and  have  not  found 
the  iodine  content  of  the  cells  measurably  different  from  that  of 
control  cells  suspended  in  Ringer's  solution. 


H.  B.  van  Dyke 


327 


Finally  autolysis  does  not  seem  to  be  much  of  a  factor  in  the 
loss — if  any  occurs — of  iodine  compounds  from  cells  as  they  lie 
in  contact  with  Ringer's  solution.  Throughout  the  process  of 
cutting  and  separating  the  cells,  the  reaction  of  the  suspending 
medium  should  remain  weakly  alkaline — a  reaction  which  has 
been  shown  to  be  unfavorable  to  autolysis.4  Also  in  experiments 
to  be  reported  later  in  which  the  same  technique  was  used  under 
slightly  different  conditions,  every  effort  was  made  to  eliminate 
autolysis  by  cutting  successively  small  portions  of  the  gland  and 
floating  the  cells  on  Ringer's  solution  cooled  by  ice.  The  cells 
from  the  small  portions  cut  successively  were  at  once  centrifu- 
galized  and  dried.  No  change  could  be  noticed  in  the  iodine 
distribution. 

Results  of  Study  of  Dog  Glands  Taken  at  Random. 

TABLE  II. 

Quantitative  Determination  of  Iodine  in  Whole  Gland  and  in  Cells  Free  from 
Colloid  Material  of  Thyroid  Glands  of  Normal  Dogs. 


Animal 
No. 

Weight 
of  whole 
gland 
used. 

Iodine 
in  whole 
gland. 

Weight 
of  cell 
mass 
used. 

Iodine 
in  cell 
mass. 

Ratio  of 
percentage 
of  iodine  in 
cells  to 
percentage 
of  iodine  in 

Morphology. 

Cells. 

Colloid. 

whole  gland. 

mg. 

per  cent 

mg. 

per  cent 

1 

5 

550.0 

0.25 

154.0 

0.031 

0.124 

Flat. 

Fair. 

6 

388.0 

0.175 

265.0 

0.027 

0.154 

ft 

Rich. 

10 

480.0 

0.017 

342.0 

0.003 

0.176 

Cuboidal. 

Poor. 

11 

505.5 

0.032 

197.5 

0.005 

0.156 

u 

" 

12* 

278.7 

0.006 

286.5 

13 

689.0 

0.234 

154.0 

0.047 

0.201 

Flat. 

Fair. 

14 

146.0 

0.187 

40.5 

0.017 

0.091 

u 

ft 

19 

474.5 

0.024 

116.0 

" 

Poor. 

20* 

287.2 

0.030 

161.5 

0.005 

0.167 

21* 

604.7 

0.038 

189.0 

0.006 

0.158 

23 

458.2 

0.003 

390.4 

Cuboidal. 

Poor. 

24 

318.7 

0.021 

295.4 

" 

" 

31 

513.8 

0.055 

205.6 

0.008 

0.145 

tt 

" 

32* 

235.2 

0.179 

103.9 

0.037 

0.207 

33 

289.3 

0.011 

538.3 

0.002 

0.182 

Flat. 

Poor. 

*  No  histological  examination. 


4  Bradley,  H.  C.,  J.  BioL  Chem.,  1915,  xxii,  113.     Bradley,  H.  C.,  and 
Taylor,  J.,  /.  BioL  Chem.,  1916,  xxv,  261. 


328  Distribution  of  Iodine  in  Thyroid  Gland.     II 

From  the  results  given  in  Table  II  one  sees  that  the  ratio  of 
iodine  concentration  in  cells  to  iodine  concentration  in  whole 
gland  (and  hence  the  ratio  of  iodine  concentration  in  cells  to 
colloid-iodine  concentration)  has  a  quite  constant  value.  In 
some  glands  (Nos.  12,  19,  23,  and  24),  to  be  sure,  the  iodine  con- 
tent of  the  cell  mass  analyzed  was  so  low  that  no  ratio  value 
could  be  obtained.  But  in  general,  despite  great  variations  in 
the  iodine  content  and  morphology  of  the  glands  analyzed,  the 
ratio  values  change  relatively  little.  These  findings  in  the  dog's 
thyroid  gland  are  similar  to  those  of  Tatum1  in  the  beef,  pig,  and 
sheep  thyroid  glands.  A  comparison  of  the  ratio  values  in  dif- 
ferent animals  is  given  below. 

Effect  of  Feeding  Iodine. 

It  was  thought  that  perhaps  ratio  changes  could  be  induced  by 
the  administration  of  iodine  or  iodine  compounds.  Capsules 
containing  1  gm.  of  potassium  iodide  or  2  drops  of  tincture  of 
iodine  in  starch  were  fed  over  varying  periods  of  time.  No  more 
than  one  capsule  was  given  in  24  hours.  The  results  of  the 
examination  of  the  glands  of  animals  so  treated  are  given  in 
Table  III. 

The  ratio  obtained  from  analyzing  the  cells  and  whole  gland  of 
the  thyroid  glands  of  animals  which  had  received  varying  amounts 
of  iodine  or  iodine  compounds  over  periods  of  no  less  than  3  days 
is  practically  the  same  as  that  of  the  animals  which  had  received 
no  iodine.  One  gland  (that  of  No.  16)  gave  an  unusually  high 
value  which  I  cannot  explain.  In  view  of  the  variations  in  mor- 
phology and  iodine  content  of  the  glands  of  the  normal  series 
together  with  the  quite  constant  ratio  exhibited  by  that  series, 
it  is  not  surprising  that  the  ratio  still  remains  constant  despite 
the  feeding  and  consequent  absorption  of  iodine.  From  a  con- 
sideration of  the  glands  examined  it  appears  that  the  ratio  is  not 
altered  by  the  feeding  of  iodine  as  potassium  iodide  or  free  iodine 
over  periods  of  time  ranging  from  3  days  to  3  weeks;  and  yet 
the  total  iodine  content  of  these  glands  undoubtedly  is  greatly 
increased  during  that  same  period. 


H.  B.  van  Dyke 


329 


TABLE  III. 

Quantitative  Determination  of  Iodine  in  Whole  Gland  and  in  Cells  Free  from 
Colloid  Material  of  Thyroid  Glands  of  Iodine-Fed  Dogs. 


Period  of  feeding. 

Ratio  of 
percent- 

!Ani- 
mal 

No. 

Form  of  iodine. 

Daily. 

On 
alter- 
nate 

Total. 

Weight 
of 
whole 
gland 
used. 

Iodine 
in 
whole 
gland. 

Weight 
of 
cell 
mass 
used. 

Iodine 
in 
cell 
mass. 

age  of 
iodine  in 
cells  to 
percent- 
age of 
iodine  in 

days.* 

whole 

gland. 

days 

days 

days 

mg. 

per  cent 

mg. 

per  cent 

2 

KI 

14 

0 

14 

98.2 

0.31 

77.7 

0.045 

0.145 

7 

KI 

14 

7 

21 

147.0 

0.12 

113.0 

0.031 

0.258 

8 

KI 

14 

7 

21 

124.5 

0.87 

125.0 

0.080 

0.092 

9 

KI 

14 

2 

16 

353.5 

0.251 

116.0 

0.040 

0.159 

16 

KI 

12 

0 

12 

651.4 

0.319 

316.1 

0.117 

0.367 

17 

KI 

Tincture  of  I. 

12 
12 

0 
0 

24 

646.5 

0.617 

302.3 

0.083 

0.134 

27 

((                    it      T 

3 

0 

3 

556.1 

0.302 

332.8 

0.046 

0.152 

29 

l(                   ((      T 

3 

0 

3 

195.2 

0.314 

158.6 

0.039 

0.124 

30 

l<                   ((      T 

3 

0 

3 

163.3 

0.357 

127.5 

0.041 

0.115 

After  feeding  daily. 


Human  Glands. 


The  distribution  ratio  of  iodine  between  cells  and  colloid  mate- 
rial was  determined  in  thirteen  human  glands  obtained  from 
operative  cases.5  In  Table  IV  are  given  the  results  of  the  anal- 
yses of  the  human  glands  together  with  the  clinical  diagnosis 
made  in  connection  with  ten  of  the  cases. 

It  will  be  seen  that  most  of  the  thyroid  glands  reported  were 
clinically  diagnosed  as  toxic  goiters.  Considerable  variations  in 
the  ratio  value  occur  and  do  not  appear  to  be  related  either  to  the 
iodine  content  of  the  gland  or  to  its  morphology.  The  ratio 
value  of  No.  22  is  inexplicably  high.  In  the  human  gland 
series,  however,  as  in  other  gland  series  previously  reported,  the 
ratio  variations  are  of  a  much  smaller  magnitude  than  the  varia- 
tions in  total  iodine  content.  So  here  too  the  ratio  is  fairly 
constant  despite  variations  in  morphology  and  iodine  content. 

6  Through  the  courtesy  of  Dr.  C.  B.  Davis  and  Dr.  A.  D.  Bevan  of  the 
Presbyterian  Hospital,  Chicago,  and  of  Dr.  A.  J.  Ochsner  of  Augustana 
Hospital,  Chicago. 


330  Distribution  of  Iodine  in  Thyroid  Gland.     II 


TABLE  IV. 


Quantitative  Determination  of  Iodine  in  Whole  Gland  and  in  Cells  Free  from 
Colloid  Material  of  Human  Thyroid  Glands. 


Series  No. 

Weight  of  whole 
gland  used. 

b 
*0 
X! 
1 

a 

'i! 

•g-a 

Weight  of  cell 
mass  used. 

1 

a 

II 
3s 

Ratio  of  percent- 
age of  iodine  in 
cells  to  per- 
centage of  io- 
dine in  whole 
gland. 

Morphology. 

Diagnosis. 

Cells. 

Colloid. 

mg. 

per 
cent 

mg. 

per  cent 

22 

284.7 

0.081 

260.8 

0.049 

0.605 

Cuboidal. 

Poor. 

Colloid      cystic 

goiter       with 

toxic      symp- 

toms. 

25* 

600.2 

0.274 

308.6 

0.105 

0.383 

Flat. 

Rich. 

Mild  exophthal- 

411.0 

0.276 

240.7 

0.098 

0.355 

mic  goiter. 

35 

671.8 

0.286 

179.2 

0.051 

0.178 

Flat. 

Rich. 

Toxic  thyroid. 

36 

439.7 

0.158 

219.9 

0.020 

0.127 

Cuboidal. 

Fair. 

"      goiter. 

37f 

667.5 

0.092 

258.4 

0.027 

0.293 

Colloid  goiter. 

38 

578.6 

0.079 

191.7 

Trace. 

Cuboidal. 

Poor. 

«                « 

following  par- 

enchymatous 

hyperplasiaof 

exophthalmic 

goiter. 

39f 

516.0 

0.279 

297.6 

0.095 

0.341 

40 

469.2 

0.345 

225.5 

0.066 

0.191 

Flat. 

Rich. 

Exophthalmic 

goiter. 

41 

559.2 

0.280 

187.0 

0.067 

0.239 

(i 

« 

48* 

549.9 

0.043 

312.4 

0.005 

0.116 

Cuboidal. 

Poor. 

607.3 

0.044 

311.3 

0.005 

0.114 

49* 

590.7 

0.137 

256.0 

0.026 

0.189 

Cuboidal. 

Fair. 

Exophthalmic 

204.5 

0.027 

0.197 

goiter. 

51 

731.4 

0.283 

294.4 

0.072 

0.254 

Flat. 

Rich. 

«         « 

60 

370.0 

0.152 

228.0 

0.015 

0.099 

it 

« 

Cystic       goiter 

with        toxic 

symptoms. 

*  Duplicate  determinations  made, 
t  No  histological  examination. 


H.  B.  van  Dyke 


331 


Comparison  of  Ratio   Value  in  Different  Animals. 

A  comparison  of  the  ratio  values  of  the  thyroid  glands  of  the 
different  animals  so  far  examined  is  given  in  Table  V.  The  few 
abnormally  high  and  unexplained  ratio  values  are  not  included  in 
the  table. 

From  what  data  are  available  there  appear  to  be  some  differ- 
ences in  the  thyroid  glands  of  different  animals  in  the  numerical 
value  of  the  ratio  of  the  percentage  of  iodine  in  cells  to  that  in 
whole  gland.  The  ratio  value  of  iodine  distribution  for  dog 
thyroid  glands  seems  to  be  consistently  lower  and  more  constant 
than  that  for  the  thyroid  glands  of  the  other  animals  studied. 

TABLE  v. 

A  Comparison  of  the  Value  of  the  Ratio  of  the  Percentage  of  Iodine  in  Cells 

Free  from  Colloid  Material  to  the  Percentage  of  Iodine  in  Whole 

Gland  in  Different  Animals. 


Animal. 

Extremes  of 
iodine  content 
of  whole  gland. 

Ratio  values. 

Extremes. 

Mean. 

Average. 

Beef*  ... 

per  cent 

0.023-0.468 
0.011-0.870 
0.043-0.345 
0.377-0.810 
0.089-0.442 

0.21  -0.48 
0.091-0.258 
0.099-0.384 
0.20  -0.34 
0.23  -0.41 

0.35 
0.175 
0.242 
0.27 
0.32 

0.36 
0.154 
0.22 
0.27 
0.33 

Doe 

Man  

Pig*f 

Sheep*  

*  Tatum.1 

t  Only  two  glands  analyzed. 


SUMMAKY. 

1.  The  method  described  by  Tatum1  was  used  to  determine 
the  ratio  of  the  percentage  of  iodine  in  cells  to  the  percentage  of 
iodine  in  whole  gland  in  the  thyroid  glands  of  normal  and  iodine- 
fed  dogs  as  well  as  in  human  thyroid  glands  obtained  from  opera- 
tive cases. 

2.  Evidence  is  presented  indicating  that  the  concentration  of 
intracellular  iodine  is  independent  of  the  suspending   medium, 
whether  that  is  pure  Ringer's  solution,  Ringer's  solution  containing 
iodine-rich  colloid  material,  or  homologous  blood  serum. 


332  Distribution  of  Iodine  in  Thyroid  Gland.     II 

3.  The  ratio  value  was  found  to  be  relatively  constant  despite 
great  variations  in  the  morphology  and  iodine  content  of  the 
glands  examined.  The  ratio  value  for  the  dog's  thyroid  gland 
seems  quite  constant  and  is  much  lower  than  that  of  the  beef  or 
sheep. 


Reprinted  from  THE  AMERICAN  JOURNAL  OF  PHYSIOLOGY 
Vol.  56,  No.  1,  May,  1921 


A  STUDY  OF  THE  DISTRIBUTION  OF  IODINE  BETWEEN 
CELLS  AND  COLLOID  IN  THE  THYROID  GLAND 

III.  THE  EFFECT  OF  STIMULATION  OF  THE  VAGO-SYMPATHETIC  NERVE 

ON  THE  DISTRIBUTION  AND  CONCENTRATION  OF  IODINE  IN  THE 

DOG'S  THYROID  GLAND 

HARRY  BENJAMIN  VAN  DYKE 

From  the  Laboratory  of  Physiological  Chemistry  and  Pharmacology,  University  of 

Chicago 

Received  for  publication  February  5,  1921 

For  many  years  it  has  been  held  that  the  thyroid  gland  is  supplied 
with  true  secretory  nerves.  In  support  of  this  assertion  there  is  con- 
siderable anatomical  evidence  and  some  physiological  evidence.  Of 
late  the  nerves  which  anatomists  have  traced  into  the  thyroid  gland  and 
have  considered  to  be  possibly  secretory  in  function  have  been  declared 
to  be  branches  of  the  cervical  sympathetic  nerve.  And  recent  physi- 
ological work  has  tended  to  confirm  this  view.  Only  twelve  years  ago 
Wiener  (1)  published  the  report  of  experiments  from  which  he  concluded 
that  extirpation  of  the  inferior  cervical  ganglion  produces  a  marked 
atrophy  of  the  thyroid  gland  on  the  side  of  the  extirpation.  Wiener 
maintained  that  no  comparable  effect  on  the  lobe  of  the  thyroid  gland 
on  the  side  of  the  operation  could  be  produced  by  vagotomy  or  by 
removal  of  the  superior  cervical  ganglion.  More  recently  Rahe  et  al.  (2) 
announced  that  they  were  able  to  produce  a  quite  marked  diminution 
in  the  iodine  concentration  of  the  lobe  of  the  thyroid  gland  on  one  side 
by  stimulating  the  thyroid  nerves  in  several  different  ways.  They 
stimulated  the  nerves  of  the  superior  thyroid  artery,  the  intact  vago- 
sympathetic  nerve  as  well  as  the  vago-sympathetic  nerve  near  the  level 
of  the  superior  cervical  ganglion  after  ligating  the  nerve  low  in  the  neck 
and  cutting  the  nerve  central  to  the  point  of  stimulation.  They  found 
that  the  most  marked  loss  was  brought  about  by  the  stimulation  of  the 
intact  vago-sympathetic  nerve. 

Watts  (3)  undertook  to  find  out  whether  or  not  the  results  obtained 
by  Rahe,  Rogers,  Fawcett  and  Beebe  might  be  due  to  vasomotor 

168 


DISTRIBUTION   OF   IODINE   IN   THYROID    GLAND  169 

changes  in  the  gland  on  the  stimulated  side.  Watts  likewise  found 
that  he  could  reduce  the  iodine  content  of  the  right  or  left  lobe  of  the 
thyroid  gland  of  the  dog  by  stimulating  the  "cervical  sympathetic  iso- 
lated from  the  vagus  sheath"  and  the  "nerve  filaments  accompanying 
the  superior  thyroid  vessels."  However  Watts  maintained  that  he 
could  cause  some  diminution  in  the  iodine  content  simply  by  periodi- 
cally reducing  the  blood  flow  through  the  gland  by  "occluding  the  main 
thyroid  artery"  the  nerves  of  which  had  been  dissected  away.  Hence 
he  concluded  that  all  of  the  effects  of  stimulation  on  the  iodine  content 
can  be  accounted  for  by  the  coincident  vasomotor  changes  which  he 
showed  to  be  present. 

Positive  evidence  of  the  secretory  effect  of  sympathetic  stimulation 
has  been  reported  by  Cannon  and  his  co-workers  (4)  in  several  communi- 
cations. Working  with  cats  they  sutured  the  phrenic  nerve  with  the 
cervical  sympathetic  nerve  and  observed  following  the  operation  in- 
creased basal  metabolism,  respiratory  hippus  and  falling  hair  which 
they  interpreted  as  the  results  of  hypersecretion  of  the  thyroid  gland 
caused  by  the  periodic  bombardment  of  the  gland  by  impulses  carried 
from  the  respiratory  center  to  the  gland's  secretory  nerves.  Cannon 
and  Cattell  (5)  adduced  additional  evidence  as  to  the  role  of  the  sympa- 
thetic nerves  in  experiments  dealing  with  the  electrical  condition  of  the 
gland.  Following  the  stimulation  of  the  upper  thoracic  sympathetic 
nerves  or  the  injection  of  epinephrin  they  were  able  to  show  a  definite 
action  current  in  the  thyroid  gland  after  a  latent  period  of  five  to  seven 
seconds.  Recently  Cannon  and  Smith  (6)  maintained  that  gentle  mas- 
sage of  the  thyroid  gland  or  stimulation  of  the  cervical  sympathetic 
nerve  increases  the  rate  of  the  denervated  heart.  The  denervated 
heart  is  said  not  to  be  affected  when  the  cervical  sympathetic  nerve  is 
stimulated  after  removal  of  the  thyroid  gland.  Moreover  Levy  (7)  ob- 
served that  the  pressor  effect  of  epinephrin  after  a  variable  latent  period 
is  increased  by  the  stimulation  of  the  cervical  sympathetic  nerve.  He 
declared  that  stimulation  of  the  cervical  sympathetic  nerve  has  no  such 
effect  after  thyroidectomy. 

However  the  conclusions  based  on  the  experiments  mentioned  above 
have  not  been  universally  accepted.  Burget  (8)  was  unable  to  alter  the 
thyroid  gland  noticeably  either  by  uniting  the  phrenic  and  cervical 
sympathetic  nerves  or  by  removing  a  section  of  the  cervical  sympathetic 
nerve.  Marine,  Rogoff  and  Stewart  (9)  sutured  together  the  phrenic 
and  cervical  sympathetic  nerves  in  several  cats.  They  demonstrated  a 
functional  union  between  the  phrenic  and  .cervical  sympathetic  nerves 


170  HARRY   BENJAMIN   VAN   DYKE 

but  observed  no  exophthalmos,  tachycardia  or  respiratory  hippus  in 
their  animals.  There  was  no  apparent  difference  either  grossly  or  his- 
tologically  in  the  lobes  of  the  thyroid  gland  on  the  operated  and  the  non- 
operated  sides.  Troell  (10)  reported  that  he  was  unable  to  produce 
either  exophthalmos  or  respiratory  hippus  by  suturing  the  proximal  end 
of  the  phrenic  nerve  to  the  cervical  sympathetic  nerve.  Employing 
cocaine  as  a  sensitizer  for  sympathetic  nerve  endings,  Mills  (11)  did 
not  observe,  following  the  repeated  injection  of  cocaine,  any  alteration 
in  the  amount  or  nature  of  the  thyroid  secretion  as  judged  by  what  is 
known  of  the  gland's  histology.  Finally  Rogoff  (12)  records  one  experi- 
ment in  which  he  drew  blood  from  a  vein  of  the  left  lobe  of  the  thyroid 
gland  and  at  the  same  time  stimulated  the  cervical  sympathetic  nerve 
on  that  side  in  the  hope  of  increasing  the  secretory  activity  of  the  stimu- 
lated lobe.  From  the  right  lobe  he  also  collected  blood  by  way  of  a 
vein.  While  drawing  the  blood  he  massaged  the  right  lobe  to  some 
extent  but  did  not  stimulate  the  right  cervical  sympathetic  nerve.  He 
found  that  specimens  of  dried  blood  from  each  lobe  were  potent  when 
fed  to  tadpoles.  But  he  could  detect  iodine  chemically  only  in  the 
blood  from  the  non-stimulated  lobe.  Moreover  the  non-stimulated  lobe 
had  a  lower  iodine  content  than  the  stimulated  lobe. 

In  connection  with  some  studies  on  the  distribution  of  iodine  in  cells 
and  colloid  in  the  thyroid  gland  I  attempted  to  alter  acutely  the  total 
iodine  content  of  the  gland  by  stimulating  the  vago-sympathetic  nerve 
of  the  dog.  Some  inconsistencies  in  the  results  in  the  early  part  of 
the  work  forced  me  to  investigate  the  matter  more  carefully  and  to 
repeat  the  work  of  Rahe  et  al.  (2)  and  of  Watts  (3). 

Methods.  Dogs  were  used  in  all  of  the  experiments.  All  except 
those  whose  numbers  are  above  that  of  no.  78  were  given  daily  feedings 
of  iodine  over  a  period  of  one  to  eleven  days.  The  daily  feeding  con- 
sisted of  a  capsule  containing  two  drops  of  tincture  of  iodine  in  starch. 
In  the  animals  fed  iodine  the  stimulation  of  the  vago-sympathetic  nerve 
was  undertaken  from  two  to  ten  days  after  the  last  feeding  of  iodine. 
Throughout  the  experiments  the  animals  were  lightly  anesthetized  with 
ether.  Platinum  wire  electrodes  were  applied  to  opposite  sides  of  the 
carefully  isolated  vago-sympathetic  nerve  and  shielded  from  all  sur- 
rounding tissues  by  glass.  In  all  of  the  experiments  except  those  re- 
corded in  table  5,  a  tetanizing  current  from  three  to  six  times  as  strong 
as  that  sufficient  to  bring  about  a  pupillary  dilatation  and  apparent 
protrusion  of  the  bulbus  oculi  was  employed.  The  regulation  of  the 
strength  of  the  current  was  made  possible  by  a  rheostat  inserted  in  the 


DISTRIBUTION    OF   IODINE    IN   THYROID    GLAND 


171 


circuit.  Again  in  all  of  the  experiments  except  those  to  be  found  in 
table  5  the  stimulating  current  throughout  the  period  of  stimulation 
was  made  for  about  0.8  second  at  intervals  of  1.6  seconds  by  means  of 
a  clock  and  ratchet  device.  The  strength  of  the  current  used  and  the 
rate  at  which  the  current  was  made  in  the  experiments  of  table  5  are 
described  below. 

TABLE  i 

Variations  in  the  iodine  content  of  neighboring  specimens  of  the  same  lobe  of  the 

thyroid  gland 


ANIMAL  NUMBER 

NUMBER  OF 
FEEDINGS  OF 
IODINE 

LOBE  OF 
THYROID  GLAND 

WEIGHT  OF  SAM- 
PLE OF  DRIED 
GLAND  ANALYZED 

IODINE   IN   DRIED 
GLAND  ANALYZED 

DIFFERENCES  IN 
THE    CONCENTRA- 
TION OF  IODINE 
IN   NEIGHBORING 
SPECIMENS  OF 
THE  SAME  LOBE 

gram 

per  cent 

per  cent 

Left 

0.1192 
0.1378 

0.331 
0.424 

0.093 

68 

11 

Right       I 

0.1525 
0.1668 

0.418 
0.455 

0.037 

/ 

/ 

0.6931 

0.366 

0.005 

Left 

0.6420 

0.371 

0.034 

I 

0.6846 

0.405 

0.039 

74 

6 

( 

0.4549 

0.370 

0.006 

Right      \ 

0.4931 

0.364 

0.019 

1 

0.5533 

0.383 

0.013 

Left 

0.4454 
0.5298 

0.121 
0.132 

0.011 

88 

0 

• 

Right      | 

0.7857 
0.4528 

0.119 
0.129 

0.010 

Left 

0.7241 
0.7138 

0.158 
0.176 

0.018 

105 

0 

Right       | 

0.4489 
0.4516 

0.163 
0.148 

0.015 

After  a  number  of  experiments  had  been  performed  it  was  found  that 
there  is  considerable  variation  in  the  iodine  content  of  adjoining  pieces 
of  the  same  gland.  In  table  1,  for  example,  are  given  a  few  analyses 
of  neighboring  specimens  of  the  same  gland.  The  differences  in  neigh- 
boring portions  of  the  glands  are  somewhat  greater  in  iodine-fed  animals. 


172 


HARRY    BENJAMIN   VAN   DYKE 


TABLE  2 

Quantitative  determination  of  iodine  in  whole  gland  and  in  cells  free  from  colloid 
material  of  thyroid  glands  of  dogs  whose  isolated  vago-sympathetic  nerve  had 
previously  been  stimulated  for  approximately  three  hours 


ANIMAL  NUMBER 

LOBE 
STIMU- 
LATED 

LENGTH  OF  PERIOD 
OF  STIMULATION 

WEIGHT  OF 
WHOLE   GLAND 
USED 

IODINE  IN  WHOLE  GLAND 

WEIGHT  OF  CELL  MASS 
USED 

IODINE  IN  CELL  MASS 

RATIO  OF  PER  CENT  OF 
IODINE  IN  CELLS  TO 
PER  CENT  OF  IODINE 
IN  WHOLE  GLAND 

APPARENT  GAIN  (+)  OK 
LOSS  (  —  )  IN  CONCEN- 
TRATION OF  IODINE  IN 
WHOLE  GLANU  OF  STIM- 
ULATED LOBE 

gram 

per  cent 

gram 

per  cent 

per  cent 

42 

Left 

2  hrs.  15  min.  < 

L     0.1792 
R    0.1693 

0.531 
0.560 

0.2533 
0.1360 

0.371 
0.303 

0.699 
0.541 

-0.029 

45 

Left 

3  hrs.    0  min.  < 

L     0.4602 
R    0.5336 

0.148 
0.102 

0.5117 
0.4750 

0.011 
0.014 

0.074 
0.137 

+0.046 

46 

"Left 

3  hrs.  30  min.  <J 

L     0.4982 
R    0.5252 

0.098 
0.104 

0.3445 

0.2284 

0.014 
0.017 

0.143 
0.163 

-O.OC6 

54 

Right 

2  hrs.  30  min.  < 

L     0.3964 
R    0.4241 

0.177 
0.147 

0.2713 
0.3883 

O.C36 
0.019 

0.203 
0.129 

-0.030 

55 

Right 

2  hrs.  40  min.  < 

L     0.6880 
R    0.5509 

0.232 
0.186 

0.2700 
0.2280 

0.031 
0.046 

0.134 
0.247 

-0.046 

56 

Right 

2  hrs.  10  min.  < 

L    0.4536 
R    0.4795 

0.121 
0.109 

0.3683 
0.3059 

0.016 
0.014 

0.132 
0.128 

-0.012 

62 

Left 

3  hrs.    5  min.  < 

L     0.0836 
R    0.0558 

0.494 
0.523 

0.0480 
O.C612 

0.078 
0.082 

0.158 
0.157 

-0.029 

64 

Right 

3  hrs.  50  min.  < 

L    0.0892 
R    0.0692 

0.110 
0.127 

0.1019 
0.1190 

0.008 
0.010 

0.073 
0.079 

+0.017 

65 

Right 

3  hrs.    0  min.  < 

L    0.1179 
R    0.1419 

0.436 
0.466 

0.1086 
0.1064 

0.037 
0.052 

0.085 
0.112 

+0.030 

66 

Right 

3  hrs.    0  min.  < 

L    0.0709 
R    0.0593 

0.485 
0.493 

0.0733 
0.0783 

0.041 
0.038 

0.085 
0.077 

+0.008 

67 

Left 

3  hrs.    0  min.  < 

L    0.1373 
R    0.1237 

0.464 
0.451 

0.1842 
0.1613 

0.041 
0.040 

0.088 
0.089 

+0.013 

68 

Left 

2  hrs.  45  min.  < 

L    0.2570 
R    0.3193 

0.377 
0.437 

0.1703 
0.1379 

0.031 
0.028 

0.082 
0.064 

-0.060 

69 

Left 

3  hrs.    0  min.  < 

L    0.5360 
R    0.3957 

0.605 
0.569 

0.2627 
0.1476 

0.083 
0.092 

0.137 
0.162 

+0.036 

71 

Right 

3  hrs.    0  min.  < 

L    0.3651 
R    0.2990 

0.346 
0.305 

0.1718 
0.1310 

0.026 
0.029 

0.075 
O.C95 

-0.041 

DISTRIBUTION    OF   IODINE   IN   THYROID    GLAND  173 

Hence  it  was  thought  desirable  to  analyze  not  single  blocks  or  sam- 
ples of  dried  powdered  mixtures  of  whole  gland  but  to  analyze  the  whole 
gland  in  each  case.  In  experiments  in  which  this  last  mentioned  tech- 
nique was  employed  the  whole  gland  was  carefully  cleaned  of  connec- 
tive tissue  and  blood  vessels,  and  thoroughly  dried  first  over  an  electric 
hot  plate  and  then  in  an  electric  oven.  After  two  to  three  hours'  dry- 
ing in  the  electric  oven  the  gland  was  broken  into  several  pieces  whose 
weight  was  about  0.5  gram  each  and  whose  number  therefore  depended 
on  the  size  of  the  gland.  The  iodine  determinations  were  made  accord- 
ing to  the  method  earlier  described  by  Kendall  (13).  By  analysis  of 
powdered  thyroid  of  known  iodine  content  the  accuracy  of  the  method 
(to  about  0.008  mgm.  of  iodine)  and  the  purity  of  the  reagents  used 
were  frequently  examined  and  found  to  be  satisfactory. 

The  strength  of  the  current  employed  in  all  of  the  experiments  re- 
corded in  table  2  was  three  times  that  sufficent  to  cause  dilatation  of 
the  pupil  and  apparent  protrusion  of  the  bulbus  oculi.  Both  the  stimu- 
lated and  the  non-stimulated  vago-sympathetic  nerves  were  cut  in 
two  places:  at  a  point  in  the  neighborhood  of  the  eighteenth  tracheal 
ring  and  also  at  a  level  a  little  above  that  of  the  hyoid  bone.  The  reason 
for  cutting  the  non-stimulated  nerve  in  such  a  manner  was  to  eliminate 
the  possible  effect  of  tonic  secretory  impulses  on  the  non-stimulated 
lobe.  The  vago-sympathetic  nerve  was  stimulated  a  little  above  the 
point  at  which  it  was  cut  low  in  the  neck.  In  the  above  experiments 
the  ratio  of  the  percentage  of  iodine  in  cells  to  the  percentage  of  iodine 
in  whole  gland  was  determined  by  a  method  previously  described  (14). 
From  the  data  given  in  table  2  it  may  be  seen  that  stimulation  of  the 
vago-sympathetic  nerve  under  the  conditions  described  is  without  ap- 
preciable effect  on  either  the  ratio  value  or  the  concentration  of  iodine 
in  the  whole  gland. 

When  it  was  found  that  there  was  no  consistent  diminution  in  the 
concentration  of  iodine  in  the  stimulated  lobe  only  the  stimulated 
vago-sympathetic  nerve  was  sectioned  in  the  manner  described  above. 
In  experiments  76,  79  and  80  a  strength  of  current  six  times  that  neces- 
sary to  cause  ocular  changes  characteristic  of  sympathetic  stimulation 
was  used;  in  all  of  the  other  experiments  to  be  found  in  table  3  the  cur- 
rent was  of  the  same  strength  as  that  used  in  the  experiments  recorded 
in  table  2.  From  the  standpoint  of  the  iodine  concentration  in  whole 
gland  the  results  given  in  tables  2  and  3  are  very  similar.  Stimulation 
apparently  has  no  effect  on  the  concentration  of  iodine  in  the  stimulated 
lobe. 


174 


HARRY   BENJAMIN   VAN   DYKE 


By  stimulating  the  intact  vago-sympathetic  nerve  Rahe  et  al.  (2)  de- 
clare that  they  were  able  to  produce  the  most  marked  diminution  in  the 
iodine  content  of  a  given  lobe  of  the  thyroid  gland.  In  the  three  experi- 
ments of  table  4  of  my  series,  the  intact  vago-sympathetic  nerve  was 

TABLE  3 

The  concentration  of  iodine  in  the  lobes  of  the  thyroid  gland  of  the  dog  after  the 
stimulation  of  the  isolated  vago-sympathetic  nerve  on  one  side  for  a  period  of 
approximately  three  hours 


ANIMAL 
NUMBER 

LOBE  STIMU- 
LATED 

LENGTH  OF  PERIOD  OF 
STIMULATION 

WEIGHT  OF 
DRIED  WHOLE 
GLAND 

IODINE  IN 
DRIED    WHOLE 
GLAND 

APPARENT   GAIN 
(+)ORLOSS(-) 
IN  CONCENTRA- 
TION OF  IODINE 
IN  STIMULATED 
LOBE 

gram 

per  cent 

per  cent 

72 

Right 

2  hrs.  50  min.    < 

L     1.2883 
R    1.4258 

0.186 
0.189 

+0.003 

74 

Right 

3  hrs.  10  min.    < 

L     2.0197 
R    1.5013 

0.381 
0.373 

-0.008 

75* 

Left 

3  hrs.  10  min. 

L     1.4975 
R    1.8796 

0.334 
0.360 

-0.026 

76 

Right 

3  hrs.  10  min.    | 

L    0.4653 
R    0.3509 

0.770 
0.821 

+0.051 

77 

Right 

3  hrs.  30  min.    < 

L    0.7055 
R    0.7914 

0.471 

0.508 

+0.037 

79 

Right 

3  hrs.  15  min.    < 

L     0.2421 
R    0.1995 

0.474 
0.498 

+0.024 

80 

Left 

4  hrs.    0  min.    < 

L     0.6342 
R    0.4850 

0.465 
0.477 

-0.012 

82 

Left 

3  hrs.  10  min.    < 

L     0.8483 
R    0.7516 

0.203 
0.206 

-0.003 

83 

Left 

3  hrs.  15  min.    \ 

L    1.2435 
R    0.9163 

0.105 
0.103 

+0.002 

84 

Left 

3  hrs.  10  min.    < 

L     0.7582 
R    0.6022 

0.129 
0.145 

-0.016 

Entire  right  lobe  not  analyzed. 


DISTRIBUTION    OF   IODINE   IN    THYROID    GLAND 


175 


stimulated  in  the  neck  at  about  the  level  of  the  fifteenth  tracheal  ring. 
The  current  was  of  the  same  strength  as  that  employed  in  the  experi- 
ments of  table  2;  each  time  the  current  was  made  there  ensued  a  respira- 
tory arrest  and  the  ocular  changes  typical  of  sympathetic  stimulation. 
Again  there  was  no  consistent  change  in  the  concentration  of  iodine  in 
the  stimulated  lobe. 

TABLE  4 

The  concentration  of  iodine  in  the  lobes  of  the  thyroid  gland  of  the  dog  after  the 
stimulation  of  the  intact  v  ago-sympathetic  nerve  on  one  side  for  a  period  of  approx- 
imately three  hours 


ANIMAL 
NUMBER 

LOBE  STIMU- 
LATED 

LENGTH  OP  PERIOD  OP 
STIMULATION 

WEIGHT  OF 
DRIED  WHOLE 
GLAND 

IODINE  IN 
DRIED  WHOLE 
GLAND 

APPARENT   GAIN 
(,+)  OR  LOSS  (—  ) 
IN  CONCENTRA- 
TION OF  IODINE 
IN  STIMULATED 
LOBE 

gram 

per  cent 

per  cent 

78 

Left 

3  hrs.  40  min.    < 

L     0.4628 
R    0.3706 

0.528 
0.501 

+0.027 

86 

Right 

3  hrs.  20  min.    < 

L     0.7039 
R    0.6919 

0.138 
0.125 

-0.013 

88 

Left 

3  hrs.  15  min.    < 

L    0:9752 
R    1.2385 

0.127 
0.123 

+0.004 

Effect  of  vasomotor  activity  on  the  concentration  of  iodine  in  the  thyroid 
gland.  It  will  be  recalled  that  Watts  (3)  concluded  from  his  experi- 
ments that  vascular  changes  will  account  for  the  diminution  in  the  con- 
centration of  iodine  which  he  brought  about  by  stimulation  of  the  cer- 
vical sympathetic  nerve.  The  experiments  of  table  5  were  undertaken 
to  find  out  whether  or  not  a  slightly  different  type  of  stimulus  sent  into 
the  nerve  at  an  interval  more  nearly  like  that  employed  by  Watts  had 
an  effect  comparable  to  that  found  in  the  experiments  previously  per- 
formed. It  was  also  thought  desirable  to  determine  whether  or  not 
the  characteristic  vascular  changes  were  present  throughout  the 
experiments. 

The  technique  except  for  certain  features  of  the  stimulation  was  the 
same  as  that  used  in  all  of  the  preceding  experiments.  Usually  the 
stimulated  vago-sympathetic  nerve  was  ligated  and  cut  at  about  the 
level  of  the  eighteenth  to  twentieth  tracheal  ring;  near  the  ganglion 
nodosum  only  the  vagus  nerve  was  cut.  In  all  of  the  experiments  the 
sympathetic  chain  was  intact  above  the  eighteenth  tracheal  ring.  The 


TABLE  5 

The  concentration  of  iodine  in  the  lobes  of  the  thryoid  gland  of  the  dog  after  the  stim- 
ulation of  the  v ago-sympathetic  nerve,  the  sympathetic  portion  of  which  was  left 
intact  above  the  point  of  stimulation 


ANIMAL 
NUM- 
BER 

LOBE  STIMU- 
LATED 

LENGTH  OF  PERIOD  OF 
STIMULATION 

PRESENCE 
(+)  OR  AB- 
SENCE (  —  ) 
OF  VA8O- 
MOTOR  AC- 
TIVITY AT 
END  OF    EX- 
PERIMENT 

WEIGHT  OF 
DRIED  WHOLE 
GLAND 

IODINE  IN 
DRIED 
WHOLE 
GLAND 

APPARENT   GAIN 
(+)ORLO8S  (  —  ) 
IN  CONCENTRA- 
TION OF   IODINE 
IN  STIMULATED 
LOBE 

grams 

per  cent 

per  cent 

101 

Right 

3  hrs.  10  min. 

-      { 

L    1.8213 
R    1.5890 

0.177 
0.125 

-0.052 

102 

Left 

3  hrs.    0  min. 

+     { 

L     0.1397 
R    0.1727 

0.141 
0.120 

+0.021 

103 

Right 

3  hrs.    0  min. 

+     { 

L    0.6335 
R    0.5749 

0.277 
0.274 

-0.003 

104 

Right 

3  hrs.    0  min. 

-      { 

L    0.1891 
R    0.1844 

0.190 
0.164 

-0.026 

105 

Right 

3  hrs.  25  min. 

+     { 

L     1.4379 
R    0.9005 

0.167 
0.156 

-0.011 

106 

Left 

3  hrs.  25  min. 

+      { 

L     0.6161 
R    0.6624 

0.043 
0.041 

+0.002 

107 

Right 

3  hrs.    0  min. 

-      { 

L    3.1065 
R    2.9642 

0.103 
0.109 

+0.006 

108 

Left 

3  hrs.  35  min. 

+     { 

L    0.3462 
R    0.2754 

0.021 
0.027 

-0.006 

109 

Right 

3  hrs.  25  min. 

*     { 

L     1.0407 
R    1.0116 

0.014 
0.016 

+0.002 

111 

Left 

3  hrs.  50  min. 

+     { 

L    0.2875 
R    0.2638 

0.076 
0.075 

+0.001 

113 

Right 

3  hrs.  30  min. 

-      { 

L     1.5649 
R    2.6585 

0.034 
0.033 

-0.001 

114 

Right 

3  hrs.  30  min. 

+     { 

L    0.3210 
R    0.3690 

0.143 
0.132 

-0.011 

115 

Left 

3  hrs.  45  min. 

+      { 

L     1.0381 
R    0.8196 

0.088 
0.090 

-0.002 

116 

Left     . 

3  hrs.  30  min. 

-      { 

L    0.6650 
R    0.6753 

0.016 
0.017 

-0.001 

117 

Left 

4  hrs.  20  min. 

+     { 

L     1.1050 
R    1.1701 

0.140 
0.134 

+0.006 

118 

Right 

5  hrs.    0  min. 

-      { 

L    0.6568 
R    0.5036 

0.456 
0.438 

-0.018 

119 

Right 

3  hrs.  10  min. 

{ 

L    0.6866 
R    0.5695 

0.168 
0.173 

+0.005 

176 


DISTRIBUTION   OF   IODINE   IN   THYROID    GLAND  177 

vago-sympathetic  nerve  was  stimulated  just  above  the  point  at  which 
it  was  cut  near  the  eighteenth  tracheal  ring.  It  was  easily  possible  to 
vary  the  strength  of  the  electrical  stimulus  so  that  a  current  of  such  a 
strength  was  employed  as  just  to  bring  about  the  ocular  changes  char- 
acteristically associated  with  stimulation  of  the  cervical  sympathetic 
nerve.  Mendenhall  (15)  has  emphasized  the  markedly  toxic  effects  of 
ether  on  the  sympathetic  nervous  system.  In  a  preparation  like  that 
last  described  the  sensitivity  of  the  cervical  sympathetic  nerve  to  the 
depressant  action  of  ether  could  easily  be  demonstrated.  A  tetanizing 
current  of  rather  low  frequency  from  a  Stoelting  inductorium  was  made 
for  5.5  seconds  at  intervals  of  11.8  seconds  throughout  the  period  of 
stimulation.  At  the  end  of  most  of  these  experiments  a  vein  of  the 
stimulated  lobe,  in  most  cases  without  the  ligation  of  its  companion 
veins,  was  cannulated  and  the  effect  on  blood  flow  of  stimulation  of  the 
gland  under  the  same  conditions  as  those  employed  in  the  experiment 
was  observed.  In  ten  out  of  sixteen  experiments  no  difficulty  was  en- 
countered in  demonstrating  a  vasoconstriction  in  the  gland  on  stim- 
ulating the  vago-sympathetic  nerve  with  an  electric  current  of  the  same 
strength  and  delivered  at  the  same  rate  as  that  used  in  the  previous 
stimulation  period.  The  threshold  of  excitability  for  the  vasoconstrictor 
nerves  of  the  thyroid  gland  appears  to  be  considerably  lower  than  that 
for  the  submaxillary  gland  as  reported  by  Gruber  (16).  The  relatively 
low  threshold  of  excitability  of  the  vasoconstrictor  nerves  of  the  thyroid 
to  epinephrin  stimulation  has  been  observed  by  Gunning  (17). 

From  table  5  it  may  be  seen  that  stimulation  of  the  vago-sympathetic 
nerve  with  the  sympathetic  trunk  intact  above  the  eighteenth  tracheal 
ring  has  no  appreciable  effect  on  the  concentration  "of  iodine  in  the  stim- 
ulated lobe.  In  a  number  of  experiments  it  was  unequivocally  demon- 
strated that  vasoconstrictor  fibers  to  the  gland  were  being  stimulated; 
yet  such  stimulation  did  not  alter  detectably  the  iodine  content  of  the 
lobe  subjected  to  stimulation. 

Effect  of  stimulation  of  the  vago-sympathetic  nerve  on  the  concentration 
of  water  in  the  thyroid  gland.  In  table  6  may  be  found  data  relative  to 
the  effect  of  stimulation  of  the  vago-sympathetic  nerve  on  the  concen- 
tration of  water  in  the  thyroid  gland.  I  was  unable  to  find  that  stimu- 
lation had  any  effect  on  the  concentration  of  water  in  the  stimulated 
lobe  even  in  experiments  in  which  vasomotor  changes  were  definitely 
proved  to  result  from  stimulation. 


178 


HARRY   BENJAMIN    VAN    DYKE 


TABLE  6 

The  concentration  of  water  in  the  lobes  of  the  thyroid  gland  of  the  dog  after  the  stimu- 
lation of  the  vago-sympathetic  nerve  for  a  period  of  from  three  to  four 

hours 


ANIMAL 
NUMBER 

LOBE 
STIMULATED 

LENGTH  OF  PERIOD  OP 
STIMULATION 

CONCENTRATION  OF 
WATER 

APPARENT  GAIN  (+) 
OR  LOSS  (  —  )  IN  CON- 
CENTRATION OF 
WATER  IN  STIMU- 
LATED LOBE 

per  cent 

per  cent 

77 

Right 

3  hrs.  30  min.      < 

L     69.25 
R    69.64 

+0.39     . 

79 

Right 

3  hrs.  15  min.      < 

L    73.40 
R    74.26 

+0.86 

82 

Left 

3  hrs.  10  min.      < 

L    74.06 
R    74.66 

-0.60 

83 

Left 

3  hrs.  15  min.      < 

L    77.57 
R    78.02 

-0.45 

84 

Left 

3  hrs.  10  min.      < 

L     74.38 
R    74.24 

+0.14 

88 

Left 

3  hrs.  15  min.      < 

L     73.65 
R    72.81 

+0.84 

108* 

Left 

3  hrs.  35  min.      < 

L    80.14 
R    80.71 

-0.57 

109* 

Right 

3  hrs.  25  min.      < 

L    78.54 
R    80.64 

+2.10 

110* 

Right 

3  hrs.  45  min.      < 

L    82.69 
R    82.13 

-0.56 

111* 

Left 

3  hrs.  50  min.      < 

L    78.03 
R    77.33 

+0.70 

113 

Right 

3  hrs.  30  min.      < 

L    75.98 
R    73.73 

-2.25 

115* 

Left 

3  hrs.  45  min.      \ 

L    75.76 
R    75.63 

+0.13 

116 

Left 

3  hrs.  30  min.      < 

L    79.92 
R     78.34 

+1.58 

117* 

Left 

4  hrs.  20  min.      < 

L    76.53 
R    75.65 

+0.88 

119 

Right 

3  hrs.  10  min. 

L    75.90 
R    76.81 

+0.91 

*  Vasomotor  effect  of  the  stimulation  demonstrated  at  the  end  of  the  experi- 
ment. 


DISTRIBUTION   OF  IODINE   IN   THYROID    GLAND 


179 


DISCUSSION 

If  we  consider  the  data  described  above  we  find  that  following  the 
stimulation  of  a  given  lobe  of  the  thyroid  gland  there  was  no  consistent 
change  in  the  concentration  of  iodine  in  that  lobe  compared  with  the 

TABLE  7 

A  comparison  of  the  effect  of  the  different  methods  of  stimulation  of  the  vago-sympa- 
thetic  nerve  on  the  concentration  of  iodine  in  the  thyroid  gland  of  the  dog 


SERIES 

NON- 

IGNIFI- 
CANT 

APPARENT  LOSS  IN  CON- 
CENTRATION OF  IODINE 

APPARENT  GAIN  IN  CON- 
CENTRATION OF  IODINE 

REMARKS 

Num- 
ber 

Maxi- 
mum 

Aver- 
age 

Num- 
ber 

Maxi- 
mum 

Aver- 
age 

per  cent 

per  cent 

per  cent 

per  cent 

I 

2 

7 

0.060 

0.035 

5 

0.046 

0.028 

Stimulated     vago-sympa- 

thetic  nerve  cut  above 

hyoid  bone  and  low  in 

the    neck.    Non-stimu- 

lated vago-sympathetic 

nerve   cut   similarly   in 

most  cases 

II 

4 

3 

0.026 

0.018 

3 

0.051 

0.037 

Only     stimulated     vago- 

sympathetic   nerve   cut 

as  in  series  I 

III 

1 

1 

0.013 

0.013 

1 

0.027 

0.027 

Intact    vago-sympathetic 

nerve     stimulated       at 

about  level  of  fifteenth 

tracheal  ring 

IV 

11 

5 

0.052 

0.024 

1 

0.021 

0.021 

Vago-sympathetic     nerve 

stimulated      at      about 

level  of  eighteenth  tra- 

cheal ring.     Sympathet- 

ic nerve  entirely  intact 

above  point  of  stimula- 

tion 

V 

7 

2 

0.011 

0.011 

1 

0.021 

0.021 

Animals   of   series   IV   in 

which  vasomotor  effect 

• 

of  stimulation  could  be 

shown  plainly  at  end  of 

experiment 

nonstimulated  lobe.  Following  stimulation  there  was  an  apparent 
diminution  in  the  concentration  of  iodine  in  24  or  54.5  per  cent  of  the 
stimulated  glands,  and  an  apparent  gain  in  20  or  45.5  per  cent  of  glands 
stimulated  similarly.  Watts  (3)  reported  that  the  average  difference 


180  HARRY   BENJAMIN   VAN   DYKE 

in  the  percentage  of  iodine  in  the  lobes  of  dried  thyroid  gland  of  the  dog 
is  0.015  per  cent  in  this  vicinity.  If  we  consider  as  non-significant  all 
differences  in  the  percentage  of  iodine  in  dried  thyroid  of  0.010  per  cent 
or  less  we  see  that  stimulation,  while  causing  an  apparent  diminution 
in  the  concentration  of  iodine  in  16  or  36.4  per  cent  of  the  glands,  and 
an  apparent  increase  in  the  concentration  of  iodine  in  10  or  22.7  per 
cent  of  the  glands,  had  no  effect  on  the  iodine  concentration  of  18  or 
40.9  per  cent  of  the  stimulated  glands.  The  greater  part  of  the  experi- 
mental data  presented  may  be  briefly  summarized  in  table  7. 

The  differences  which  I  found  above  appear  to  be  due  to  normal 
variations  in  the  concentration  of  iodine  in  the  two  lobes  of  the  dog's 
thyroid  gland.  The  average  percentage  difference  in  the  concentration 
of  iodine  in  the  two  lobes  of  the  dog's  thyroid  gland  depends  on  a  num- 
ber of  factors  such  as  the  type  of  gland,  the  time  of  year  and  the  feed- 
ing of  iodine.  Hence  I  am  forced  to  conclude  that  if  stimulation  of  the 
vago-sympathetic  nerve  in  the  dog  has  any  effect  on  the  concentration 
of  iodine  in  the  thyroid  gland,  that  effect  is  considerably  less  than  the 
normal  variation  in  the  iodine  content  of  the  stimulated  and  control 
lobes.  The  presence  of  normal  variations  relatively  so  much  greater 
than  the  variations  which  may  follow  stimulation  renders  valueless  the 
application  of  more  refined  methods  of  iodine  determination  in  the  study 
of  the  effect  of  stimulation  of  the  cervical  sympathetic  nerve  on  the 
concentration  of  iodine  in  the  thyroid  gland. 

SUMMARY 

1.  Periodic  stimulation  of  the  isolated  vago-sympathetic  nerve  by 
an  induced  current  of  a  moderate  to  strong  intensity  over  a  period  of 
from  three  to  three  and  a  half  hours  does  not  appreciably  alter  the 
distribution  ratio  of  iodine  between  cells  and  colloid. 

2.  The  findings  of  Rahe,  Rogers,  Fawcett  and  Beebe  (2)  and  of  Watts 
(3)  that  stimulation  of  the  cervical  sympathetic  nerve  for  a  comparable 
period  of  time  reduces  the  concentration  of  iodine  in  the  stimulated 
lobe  were  not  confirmed.    Watts'  assertion  that  such  stimulation  reduces 
the  water  content  of  the  stimulated  lobe  was  not  confirmed. 

3.  Conclusions  as  to  the  direct  secretory  control  which  the  cervical 
sympathetic  nerves  exercise  on  the  thyroid  gland  are  based  in  no  small 
measure  on  the  alleged  effect  of  stimulation  of  the  cervical  sympathetic 
nerve  on  the  iodine  content  of  the  gland.     Conclusions  having  such  a 
basis  apparently  are  untenable. 


DISTRIBUTION   OF  IODINE   IN   THYROID    GLAND  181 

It  is  a  pleasure  to  acknowledge  the  many  suggestions  and  constant 
aid  given  me  by  Dr.  A.  L.  Tatum  during  the  progress  of  this  work. 

BIBLIOGRAPHY 

(1)  WIENER:  Arch,  exper.  Path.  u.  Pharm.,  1909,  Ixi,  297. 

(2)  RAHE,  ROGERS,  FAWCETT  AND  BEEBE:  This  Journal,  1914,  xxxiv,  72. 

(3)  WATTS:  This  Journal,  1915,  xxxviii,  356. 

(4)  CANNON,  BINGER  AND  FITZ:  This  Journal,  1915,  xxxvi,  363. 
CANNON  AND  FITZ:  This  Journal,  1916,  xl,  126. 

(5)  CANNON  AND  CATTELL:  This  Journal,  1916,  xli,  58,  74. 

(6)  CANNON  AND  SMITH:  Endocrin.,  1920,  iv,  386. 

(7)  LEVY:  This  Journal,  1916,  xli,  492. 

(8)  BURGET:  This  Journal,  1917,  xliv,  492. 

(9)  MARINE,  ROGOFF  AND  STEWART:  This  Journal,  1918,  xlv,  268. 

(10)  TROELL:  Arch.  Int.  Med.,  1916,  xvii,  382. 

(11)  MILLS:  This  Journal,  1919,  1,  174. 

(12)  ROGOFF:  Journ.  Pharm.  Exper.  Therap.,  1918,  xii,  193. 

(13)  KENDALL:  Journ.  Biol.  Chem.,  1914,  xix,  251. 

(14)  TATUM:  Journ.  Biol.  Chem.,  1920,  xlii,  47. 

(15)  MENDENHALL:  This  Journal,  1914,  xxvi,  57. 

(16)  GRUBER:  This  Journal,  1915,  xxxvii,  259. 

(17)  GUNNING:  This  Journal,  1917,  xliv,  215. 


Reprinted  from  THE  JOURNAL  OF  BIOLOGICAL  CHEMISTRY 
Vol.  LIV,  No.  1,  September,  1922 


A  STUDY  OF  THE  DISTRIBUTION  OF  IODINE  BETWEEN 
CELLS  AND   COLLOID  IN  THE  THYROID   GLAND. 

IV.  THE  DISTRIBUTION  OF  IODINE  IN  THE  HYPERPLASTIC  THY- 
ROID GLAND  OF  THE  DOG  AFTER  THE  INTRAVENOUS 
INJECTION  OF  IODINE  COMPOUNDS. 

BY  HARRY  BENJAMIN  VAN  DYKE. 

(From  the  Laboratories  of  Pharmacology,  University  of  Chicago,  Chicago.) 

(Received  for  publication,  July  20, 1922.) 

Some  years  ago  Marine  and  Feiss  (1)  and  Marine  and  Hogoff 
(2,  3)  first  performed  experiments  which  leave  little  doubt  as  to  the 
ability  of  the  dog's  thyroid  gland,  especially  when  hyperplastic, 
to  bind  iodine  almost  instantaneously.  Marine  and  Feiss  (1) 
carefully  perfused  the  surviving  thyroid  gland  with  fluid  con- 
taining iodine  as  KI.  They  found  that  after  1  hour  a  consider- 
able amount  of  iodine  was  taken  up  only  by  a  surviving  gland. 
Any  evidence  of  death  of  the  perfused  organ  was  accompanied  by 
a  loss  of  some  of  the  gland's  stored  iodine  rather  than  by  an 
absorption  of  iodine  from  the  circulating  medium.  However,  even 
a  surviving  gland,  rich  in  iodine,  lost  some  iodine  to  a  perfusing 
fluid  free  of  the  element.  In  surviving  glands  they  discovered 
that  the  amounts  of  iodine  absorbed  were  relatively  independent 
of  the  amounts  of  iodine  in  the  perfusing  fluids.  They  also  pointed 
out  that  a  similarly  rapid  absorption  of  iodine  by  the  intact  gland 
follows  the  intravenous  administration  of  a  solution  of  KI.  From 
the  results  of  perfusions  of  spleen  and  kidney  under  similar  condi- 
tions they  concluded  that  these  organs  were  not  capable  of  taking 
up  a  significant  amount  of  iodine. 

Marine  and  Rogoff  (2)  on  the  basis  of  experiments  in  which 
they  injected  a  solution  of  KI  intravenously  came  to  the  con- 
clusion that  the  absorption  of  iodine  by  the  gland  is  almost  as  great 
1  hour  after  the  injection  as  it  is  30  hours  after  the  injection. 
They  again  found  that  no  significant  amount  of  iodine  was  taken  up 
by  the  spleen  and  liver.  The  amount  of  iodine  absorbed  by  the 

11 


12  Iodine  in  the  Thyroid  Gland 

thyroid  gland  appeared  to  be  directly  proportional  to  the  degree 
of  hyperplasia  exhibited  by  the  gland.  In  a  second  communica- 
tion (3)  they  discussed  the  time  of  appearance  of  the  changes  in  the 
histology  and  physiological  activity  of  the  gland  following  the 
intravenous  administration  of  KI  solution. 

Having  found  (4)  that  there  was  relatively  little  difference  in 
the  ratio  of  the  percentage  of  iodine  in  cells  to  the  percentage  of 
iodine  in  whole  gland  in  dog  thyroid  glands  exhibiting  great 
variations  in  histological  appearance  and  iodine  content,  I  under- 
took the  present  study  to  determine  what  effect  acute  iodization  of 
hyper  plastic  thyroid  glands  has  on  the  ratio  value. 

Methods. 

As  in  the  work  of  Marine  and  Feiss,  and  Marine  and  Rogoff, 
dogs  with  thyroid  glands  usually  definitely  hyperplastic  were 
used  in  all  of  the  experiments.  Light  ether  narcosis  was  always 
employed.  All  solutions  of  KI  and  thyroid  colloid  were  injected 
into  the  femoral  vein.  Every  effort  was  made  to  section  the  glands 
as  rapidly  as  possible  after  their  removal  from  the  animal.  In 
the  making  of  the  determinations  of  the  ratio  of  the  percentage 
of  iodine  in  dried  cells  to  that  in  dried  whole  gland  the  method 
first  described  by  Tatum  (5)  was  somewhat  modified.  To  lessen 
autolysis  as  much  as  possible  the  glands  on  removal  were  plunged 
into  Ringer's  solution  cooled  to  1^°C.  The  glands  were  then 
carefully  cut  into  blocks  of  a  size  appropriate  for  the  floor  of  the 
freezing  microtome  and  frozen  sections  were  made  of  a  considerable 
amount  of  tissue.  The  blocks  of  tissue  cut  for  the  microtome's 
floor  as  well  as  the  cut  sections  were  suspended  in  Ringer's  solution 
cooled  to  1-4°C.  As  in  the  preceding  work  of  this  series  the  frozen 
sections  were  cut  sufficiently  thin  so  that  practically  all  of  the 
colloid  or  intercellular  fluid  was  dissolved  out  of  the  acini  as  soon 
as  the  sections  were  suspended  in  cooled  Ringer's  solution.  By 
centrifugalization  the  cells  were  separated  from  the  colloid  dissolved 
in  the  Ringer's  solution  and  carefully  dried  over  an  electric  hot- 
plate and  then  in  an  electric  drying  oven.  Control  pieces  of 
uncut  whole  gland  were  also  dried  in  the  same  manner.  Through- 
out this  paper  colloid  iodine  solutions  refer  to  cell-free  solutions  of 
thyroid  intercellular  fluids  obtained  by  the  method  just  described 
and  dissolved  in  Ringer's  solution.  In  all  of  the  experiments  the 


H.  B.  van  Dyke  13 

quantitative  determinations  of  iodine  were  made  by  the  method 
of  Kendall  (6). 

From  the  data  of  Table  I  it  can  be  seen  that  large  amounts  of 
iodine  as  KI  were  taken  up  by  hyperplastic  thyroid  glands  despite 
big  variations  in  the  dose  of  KI  (50  to  150  mg.)  and  duration  of  time 
between  injection  and  removal  of  gland  (90  seconds  to  22  hours 
and  25  minutes).  The  cooling  of  the  blocks  of  thyroid  tissue  dur- 
ing the  process  of  cutting  had  little  effect.  Either  little  of  the 
injected  iodine  was  held  by  the  cells,  or  it  diffused  rapidly  from  the 
cells  in  the  process  of  cutting;  for  the  iodine  content  of  the  cells 
and  hence  the  ratio  of  the  precentage  of  iodine  in  cells  to  the  per- 
centage of  iodine  in  whole  gland  is  considerably  less  than  that 
found  in  resting  glands.  The  average  ratio  value  of  0.15  for  the 
dog  (4)  was  approached  only  in  Experiment  11  in  which  nearly 
24  hours  elapsed  between  the  injection  of  KI  and  the  removal  of 
the  experimental  lobe.  In  this  last  case  there  are  alternative 
means  of  explanation:  more  iodine  may  have  been  bound  by  the 
cells  by  removal  from  the  thyroid's  intercellular  spaces,  or  the  iodine 
in  the  cells  was  in  a  less  diffusible  form  than  in  the  other  experi- 
ments of  the  series.  These  changes  in  the  distribution  of  iodine 
after  about  24  hours  can  be  definitely  correlated  with  Marine  and 
Rogoffs  (3)  discovery  that  20  hours  after  the  injection  of  iodine  as 
KI,  markedly  hyperplastic  glands  exhibit  more  stainable  colloid 
with  some  increase  in  the  size  of  the  follicular  spaces  and  shrinkage 
in  the  height  of  the  columnar  epithelium. 

In  the  experiments  the  data  of  which  are  given  in  Table  II, 
solutions  of  colloid  iodine  from  normal  dog  thyroid  glands  were 
injected  intravenously  to  determine  to  what  extent  iodine  in 
organic  combination  is  bound  by  hyperplastic  thyroid  glands. 

The  iodine  of  thyroid  colloid  of  normal  animals  is  practically 
not  at  all  taken  up  by  hyperplastic  glands  after  42  to  86  minutes. 
A  comparable  amount  of  iodine  in  the  form  of  KI  is  rapidly 
taken  up. 

Blum  and  Griitzner  (7)  found  some  hours  after  the  injection 
into  the  circulatory  system  of  fluid  pressed  from  thyroid  glands 
that  the  iodine-containing  thyroid  protein  is  split  largely  by 
hepatic  action  into  simpler  products  with  the  formation  even 
of  iodides.  In  Experiments  12  and  13  (42  and  86  minutes  after 
intravenous  injection)  there  is  little  evidence  that  much  iodide- 


TABLE  I. 


Ratio  of  the  Percentage  of  Iodine  in  Cells  to  the  Percentage  of  Iodine  in  Whole 

Glands  in  Hyperplastic  Thyroid  Glands  of  Dogs  Receiving  an 

Intravenous    Injection    of   KI   Solution  for    Varying 

Lengths  of  Time  before  the  Removal  of  the  Glands. 


Animal  No. 

p 

H 

*o 

11 

I.I 

<!  " 

if8 

m 
| 

°c    -6 

till 

H 

1 

r 

«*-T) 
°8 

I] 
jg* 

rS 
13 
^3 
* 

a 

si 
p 

9 

1 

"8 

11 

3  3 

£ 

Iodine  in  cell  mass. 

Ratio  of  per  cent  of 
iodine  in  cells  to 
per  cent  of  iodine 
in  whole  gland. 

mg. 

sec. 

gm. 

per  cent 

gm. 

per  cent 

1 

50 

90 

Control. 

0.6786 

0.021 

0.5242 

0 

Iodized. 

0.5553 

0.042 

OT7845 

0.002 

0.048 

2 

50 

150 

Control. 

0.6548 

0.010 

0.6373 

0 

Iodized. 

0.5695 

0.072 

0.8437 

0.003 

0.042 

tm'n. 

3* 

135 

57 

Control. 

0.6797 

0 

0.3585 

0 

Iodized. 

0.4808 

0.086 

0.5449 

0 

4 

120 

60 

Control. 

0.4512 

0.042 

0.3775 

0 

Iodized. 

0.7760 

0.079 

0.4702 

0 

5 

150 

60 

Control. 

0.6853 

0 

0.6105 

0 

Iodized. 

0.6302 

0.078 

0.7473 

0 

6 

50 

60 

Control. 

0.8779 

0.002 

0.5694 

0 

Iodized. 

0.8314 

0.059 

0.8021 

0.004 

0.068 

7 

50 

60 

Control. 

0.8130 

0 

Iodized. 

0.652 

0.085 

0.6994 

0.002 

0.025 

0.731 

0.070 

8 

50 

60 

Control. 

0.408 

0.007 

0.649 

0.004 

, 

Iodized. 

0.461 

0.081 

0.8222 

0.004 

0.045 

0.245 

0.098 

9 

150 

64 

Control. 

0.515 

0.002 

0.7066 

0 

Iodized. 

0.595 

0.085 

0.8282 

0.003 

0.035 

10* 

120 

70 

Control. 

0.345 

0.010 

0.245S 

0 

Iodized. 

0.250 

0.091 

0.2627 

0 

hrs.  min 

• 

11 

50 

22      2 

Control. 

0.465 

0.017 

0.5357 

0 

0.571 

0.020 

Iodized. 

0.719 

0.213 

0.5422 

0.022 

0.103 

*  Glands  and  cells  not  suspended  in  ice-cooled  Ringer's  solution. 

14 


H.  B.  van  Dyke 


15 


iodine  has  been  split  from  colloid  iodine;  for  the  hyperplastic 
thyroid  glands  present  exhibit  no  significant  change  in  iodine  con- 
tent and  yet  are  able  quickly  to  bind  any  iodine  available  as  iodide. 
In  the  experiments  reported  in  Table  III  colloid  iodine  solution 
of  animals  with  hyperplastic  glands,  each  of  which  had  received  an 

TABLE  II. 

Ratio  of  the  Percentage  of  Iodine  in  Cells  to  the  Percentage  of  Iodine  in 
Whole  Gland  in  Hyperplastic  Thyroid  Glands  of  Dogs  after  the  Intrav- 
enous Injection  of  Thyroid  Colloid  Iodine  from  Normal  Dog 
Thyroid  Glands.     The  Iodine  Content  of  a  Hyperplastic 
Gland  of  a  Dog  after  the  Injection  of  a  Comparable 
Amount  of  Inorganic  Iodine  is  also  Recorded. 


a 

c 

III 

1 

1 

I** 

1 

o> 

-^S^ 

•i 

I 

S 

i 

o|| 

| 

1 

0 

11 

t 

1 

•8 

nt  of  iodin 

elapsing 
pletion  of 
removal 

•8 

s  in  whole  t 

t  of  cell  m: 

• 

a 
1 

a 

rtl 

g 

a 

g 

®  a^Ja 

0 

'S'o 

a 

s 

c 

i  1 

'3 

<J  ~" 

.  i 

'4 

H003"2 

1 

'Is 

1 

1 

1 

I'5"3 

cc. 

m0. 

min. 

am. 

per 
cent 

am. 

per 
cent 

12 

200.0 

Colloid 

1.690 

42 

Control. 

0.6565 

0.002 

0.5478 

0.001 

iodine. 

Iodized. 

0.6248 

0.002 

0.4819 

0 

13 

259.6 

Colloid 

2.829 

86 

Control. 

0.7971 

0 

0.7698 

0 

iodine. 

0.8557 

0 

• 

Iodized. 

0.4742 

0.005 

0.9208 

0 

0.4245 

0 

14 

241.5 

KI 

2.087 

46 

Control. 

0.7939 

0.003 

0.6024 

0.004 

,. 

Iodized. 

0.4513 

0.017 

0.5907 

0.019 

intravenous  injection  of  50  mg.  of  KI  60  minutes  before  the  removal 
of  the  thyroid  lobe  for  section,  was  injected  intravenously  as  soon 
as  possible  into  other  animals  with  hyperplastic  glands.  The 
sequence  was  as  follows:  as  a  control,  part  of  one  lobe  was  removed; 
colloid  iodine  dissolved  in  Ringer's  solution  was  then  injected  and 
all  but  half  of  one  lobe  resected;  a  comparable  amount  of  iodine 
as  KI  dissolved  in  a  similar  amount  of  Ringer's  solution  was  then 


16 


Iodine  in  the  Thyroid  Gland 


TABLE  III. 

Ratio  of  the  Percentage  of  Iodine  in  Cells  to  the  Percentage  of  Iodine  in  Whole 

Gland  in  Hyperplastic  Thyroid  Glands  of  Dogs  after  the  Intravenous 

Injection  of  Thyroid  Colloid  Iodine  from  Hyperplastic  Thyroid 

Glands  Iodized  but  a  Short  Time  before  Being  Sectioned. 


i 

6*0  £ 

TJ 

J.o 

•** 

—i        £ 

• 

•d 

•s 

§1  *. 

•3 

•d 

3I'ST3 

q 

ii 

_o 

c 

j 

"o'c  § 

"3 

'ui 

• 

•^  o  "^b 

6 

ii 
•gi 

iil 

ja 

0 

J 

S 
1 

S 
1 

§  £.2 

Sol 

Animal  K 

it 
ii 
f 

J*s  *  • 

^u          *& 

I'll! 

1 

11 

jjjj 

'i 
1 

"8 

f 

Iodine  in 

Ratio  of  ] 
in  cells 
£Ldine  in 

min. 

gm. 

per  cenf 

gm. 

per 
cent 

15 

0.820  mg.  of  col- 

60 

Control. 

0.6022 

Trace. 

loid   iodine    of 

Colloid 

0.6986 

0.009 

1.1376 

0 

Animal  7*   dis- 

iodine. 

0.7186 

0.009 

solved  in  233  cc. 

of        Ringer's 

solution. 

0.836      mg.      of 

25 

KI 

0.8328 

0.017 

KI  dissolved  in 

0.6935 

0.022 

253.5     cc.     of 

Ringer's    solu- 

tion. 

16 

0.908  mg.  of  col- 

40 

Control. 

0.4700 

0 

loid    iodine    of 

Colloid. 

0.4015 

0.006 

1.1110 

0 

Animal  8*  dis- 

iodine. 

0.3695 

0.007 

solved  in  318  cc. 

, 

of        Ringer's 

solution. 

0.827  mg.  of  KI 

6 

KI 

0.4581 

0.009 

dissolved        in 

0.4437 

0.010 

318  cc.  of  Ring- 

er's solution. 

*  See  Table  I. 

injected  and  the  remaining  half  of  one  lobe  taken  out.  Much 
more  of  the  iodine  from  the  colloid  iodine  of  these  animals  was 
taken  up  than  from  the  colloid  iodine  of  normal  animals  (Table  II). 


H.  B.  van  Dyke  17 

Even  here  considerable  iodine  as  KI  was  still  bound  by  the  glands 
which  had  taken  up  some  colloid  iodine.  These  results  suggest 
that  the  colloid  iodine,  bound  but  incompletely  synthesized  into 
active  principle,  is  in  a  more  diffusible  form  in  the  acutely  iodized 
gland  than  in  the  more  normal  resting  gland.  Moreover,  the 
incompletely  synthesized  active  principle  may  be  more  readily 
split  by  hepatic  action  (7)  into  simpler  products  (e.g.,  iodides) 
which  are  then  bound  by  the  hyperplastic  thyroid  gland. 

Marine  and  Rogoff  (3)  declare  that  even  30  hours  after  intra- 
venous administration  of  a  solution  of  KI  very  little  of  the  thyroid's 
active  principle,  as  measured  by  the  effects  of  thyroid  on  tadpole 
growth  and  metamorphosis,  has  been  elaborated.  The  less 
diffusible  and  less  readily  split  normal  colloid  iodine  compound 
(Table  II)  probably  represents  the  more  fully  elaborated  active 
principle. 

SUMMARY. 

The  findings  of  Marine  and  Feiss  and  Marine  and  Rogoff  that 
the  hyperplastic  thyroid  gland  of  the  dog  rapidly  bincls  iodine 
intravenously  introduced  as  a  solution  of  KI  were  confirmed. 

By  a  method  already  described  (5)  the  ratio  value  of  iodine  in 
cells  to  iodine  in  whole  gland  was  determined  and  found  to  be  very 
low  after  the  intravenous  injection  of  KI  solution  into  dogs  with 
hyperplastic  glands  when  those  glands  were  removed  1.5  to  60 
minutes  after  the  injection.  The  ratio  value  more  nearly  ap- 
proached the  normal  if  the  interval  elapsing  between  injection 
and  removal  of  gland  was  made  about  24  hours  instead  of  1  hour 
or  less  as  in  most  of  the  experiments.  This  finding  is  in  keeping 
with  the  histological  changes  described  by  Marine  and  Rogoff  in 
such  glands  20  hours  after  the  intravenous  injection  of  KI  solution. 

When  iodine  as  colloid  iodine  solution  of  normal  animals  was 
administered  intravenously  practically  none  of  the  colloid  iodine 
was  taken  up  by  hyperplastic  glands  during  the  periods  of  time 
used  in  these  experiments;  yet  from  an  injection  of  a  comparable 
amount  of  iodine  in  the  form  of  KI  the  ready  binding  of  iodine  by 
similarly  hyperplastic  glands  was  proved.  Colloid  iodine  of 
hyperplastic  glan'ds  removed  1  hour  after  the  intravenous  injection 
of  KI  solution  was  taken  up  to  some  extent  by  hyperplastic  glands; 
but  these  last  named  glands  bound  additional  iodine  as  KI  intro- 


18  Iodine  in  the  Thyroid  Gland 

duced  after  the  colloid  iodine  injection.  The  incompletely 
synthesized  active  principle  is  probably  more  diffusible  and  more 
readily  split  into  simpler  products  than  active  principle  fully 
synthesized. 

BIBLIOGRAPHY. 

1.  Marine,  D.,  and  Feiss,  H.  O.,  /.  Pharmacol.  and  Exp.  Therap.,  1915,. 

vii,  557. 

2.  Marine,  D.,  and  Rogoff,  J.  M.,  J.  Pharmacol.  and  Exp.  Therap. ,  1916, 

viii,  439. 

3.  Marine,  D.,  and  Rogoff,  J.  M.,  /.  Pharmacol.  and  Exp.  Therap.,  1916-17, 

ix,  1. 

4.  van  Dyke,  H.  B.,  J.  Biol.  Chem.,  1920-21,  xlv,  325. 

5.  Tatum,  A.  L.,  J.  Biol.  Chem.,  1920,  xlii,  47. 

6.  Kendall,  E.  C.,  J.  Biol.  Chem.,  1914,  xix,  251. 

7.  Blum,  F.,  and  Griitzner,  R.,  Z.  physiol.  Chem.,  1920,  ex,  277. 


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:    nun 

AUGll  1941 

rtrT  i   f  4OvM 

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/FCB  i;?  1974 

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